Broadly speaking, thin film transistors (TFT's) are known. TFTs are useful in controlling various types of display, e.g., liquid crystal or electrophoretic displays and the like. Generally speaking, TFT's are commonly fabricated on rigid substrates, commonly glass. However, there is increasing interest in fabricating TFT's on flexible substrates, especially flexible polymeric films, due to lower weight and improved ruggedness (relative to glass). TFT's based upon amorphous silicon semiconductors are attractive for use on such flexible substrates since they allow fabrication with a relatively low number of process steps and with a relatively low thermal budget. However, polymeric films generally do not have sufficient thermal or dimensional stability for such TFT applications. Hence, there is an ever increasing interest in the industry to find a polymer substrate that can act as a substitute for glass in a TFT application, particularly where the polymeric substrate is able to lower overall cost, improve performance, decrease weight, increase ruggedness and simplify manufacture. U.S. Pat. No. 6,825,068 to Denis, et al. is directed to semiconductor composites where semiconductive amorphous silicon is fabricated on substrates comprising polyphenylene polyimides.